Solar power stations proposed to date have been subjected to a variety of design problems some of which are as follows:
The area covered by the power station needs to be 200-400 times larger than a conventional power station; PA1 Flat surfaces are essential for structural simplicity of solar collectors and for maximum utilization of solar radiation; PA1 Tracking of the solar collectors to follow the sun requires complex mechanical systems; PA1 Contamination of the air reduces incident radiation and leads to deposits of dirt on the collector surfaces; PA1 Cooling towers utilized to condense working fluid of turbines require a multiple of heat exchange surface areas compared with those of conventional power stations; PA1 The cost of known forms of heat storage for storing heat during nighttime or cloudy periods is much higher than that of a complete nuclear power station of comparable power output. PA1 only the open sea offers unlimited areas for solar collectors free of cost; PA1 only the open sea offers horizontal flat surfaces; PA1 the diurnal rotation of a collector platform fulfills the sun-tracking requirement; PA1 provided the distance from the shore is adequate, there is no air contamination and consequently no dirt deposited on the collectors; and PA1 condenser cooling by cold depth water replaces not only the entire cooling tower installation of conventional power stations but also increases the thermodynamic cycle efficiency.
Attempts have been made to overcome some of these problems. For example equipment has been proposed in which solar radiation is focussed by reflectors which are tracked in the direction of the sun in the vertical elevation as well as in the horizontal azimuth by complicated mechanical means. Solar collectors in the form of blackened foil cushions have been proposed which are stretched over hot water storage accumulators and float on a water surface.
It is known to utilize parabolic mirrors to concentrate solar energy on ducts situated at the focal axes of the mirrors and where the ducts convey a fluid heat carrier. Insofar as the collectors heat a heat carrier flowing through them, the known collectors are built as rigid mechanical structures. For reasons of strength, these collectors have to be relatively small and owing to the low energy flux density of solar radiation, only relatively small power flows can be economically converted by a collector which is limited in size. The conversion of solar thermal energy to electricity can only be accomplished economically if power flows are made available in a magnitude similar to those of conventional power stations. This need requires solar collectors having dimensions measured in square kilometers.
It is therefore an object of our invention to provide for a solar power station which may have a power output similar to that of a conventional power station.